Wellhead assembly



United States Patent John H. Fowler Houston, Texas Oct. 19, 1966 Sept.29, 1970 Rockwell Manufacturing Company, Houston, Tex.,

a corporation of Pennsylvania lnventor Appl. No. Filed Patented AssigneeWELLHEAD ASSEMBLY 4 Claims, 3 Drawing Figs.

u.s. Cl 137/608, 137/236 lnl.Cl [52") 41/00 Field ol'SearchW 251/367(Cursory),

31 (Cursory); 137/608 (Cursm'y); 137/236,

608: 61/(lnquired); 251/57: 63.5. 63.6

References Cited UNITED STATES PATENTS 2,641,280 6/1953 Fleischhauer137/625 3,2l2,5l6 l0/l965 Natho a ..137/236(OS)UX 3,367,355 2/1968Anderson r 137/236X 3,400,730 9/1968 Anderson 137/236 PrimaryExaminerJohn P. McIntosh Attorneys- Robert W. B. Dickerson, MurrayRobinson, Ned

L. Conley and James A. Bargfrede ABSTRACT: An underwater wellheadassembly comprising a plurality of valves connected by an adapter. Eachvalve has a fluid-actuable operator thereon. A control means in thewellhead controls flow of operating fluid to and from the operators.Passageways are formed in the walls of the adapter, valves and operatorsconnecting the control means to the operators without external conduits.

Patented Sept. 29, 1970 Sheet 1 of 3 (156/7 aw/er INVENTOR.

' i Arromvsr -1 Patented Sept. 29, 1970 t I v 3,530,885

Sheet 2 of 3 J b 20 Fow/sr L ENTOR.

Sheet (fa/2n f'aw/ex' LWENTUR.

WELLHEAD ASSEMBLY This invention relates to fluid operated systems, andmore particularly it pertains to hydraulic and pneumatic systems for usewith fluid operated equipment on well heads positioned at offshorelocations.

In an attempt to locate new oil fields, an increasing amount of welldrilling has been conducted at offshore locations such as, for example,off the coasts of Louisiana, Texas and California. Usually the stringsof pipe in such offshore wells extend to a point above the surface ofthe water where they are closed in a conventional manner that is used inland wells with a conventional wellhead assembly being attached to thetop of the casing. Recently, however, attempts have been made to providemethods and apparatus for drilling and completing a well wherein boththe well casinghead and the wellhead assembly are located under water ata depth sufficient to allow ships to pass over them. Preferably, thesepieces of equipment are located close to the ocean floor. Thus it hasbeen necessary to design entirely new equipment for this purpose. Amongother equipment, it has been'necessary to design new wellhead assembliesfor controlling the flow of fluid from producing wells. As is well knownin the art, such assemblies are commonly called Christmas trees".

On land the various components of a wellhead assembly for controllingflow are often manually operated so as to achieve the desired productionfrom the well. However, where the wellhead is positioned under water,such as close to the ocean floor, the various elements of the wellheadassembly are preferably arranged for remote control by electrical,hydraulic or pneumatic systems.

It will be appreciated that two fluid lines will normally be required tooperate any single moving element of a fluid operated device in awellhead. Thus, where a wellhead as sembly contains severalhydraulically operated devices, as is usually the case, it is normallynecessary to provide a large number of hydraulic lines extending fromthe wellhead assembly below the water to the operating base above thewater. Often as many as or more of such hydraulic lines are required forone wellhead assembly. It will be appreciated that such hydraulic linesmust be of flexible construction and of suitable materials to extendfrom the underwater wellhead to the base located at the surface of thewater while at the same time being able to resist deterioration by seawater. Also each connection to the wellhead assembly provides a separatepoint of possible leakage and/or corrosion by the sea water, and aseparate point which might be damaged during the lowering of V I aChristmas tree," for example, into position, and a separate wellheadassembly utilizing only a single exposed fluid line for operation of allfluid operated devices thereon.

Another'object of this invention is to provide a wellhead assembly inwhich fluid connections between various components of the assembly areenclosed within the components themselves, so that there are no externalconduits for conducting operating fluid except those between theChristmas tree and the surface.

Still another object of this invention is to greatly simplify and reducethe time required for positioning a Christmas tree" or other wellheadassembly in place and readying it for operation in an underwaterlocation. 7 For better understanding of the foregoing and other objectsof the invention, reference is now made to the accompanying drawings,wherein FIG. I is an elevational view ofa Christmas tree utilizing oneembodiment ofthe invention,

FIG. 2 is another view of the Christmas tree" shown in FIG. 1 with partsbroken away, and I FIG. 3 is a partially sectioned view of one valve andoperator therefor embodying one form of the invention.

The Christmas tree" shown in FIGS. 1 and 2 comprises an assembly of amaster valve 14, a swab valve 16 and a wing valve 18 connected togetherby means of an adapter tee 20 between the swab valve and master valve.The master valve is connected through a clamp 12 to an adapter flange l0affixed to the top of the well. A valve operator 22 is also connected tothe tee 20 and provides means for operating each of the I valves. In theembodiment shown, the valves are connected to the tee by means of clamps24. Similar clamps 26 connect a production line 28 to the wing valve 18and a plug 30 to the outlet of swab valve 26.

Valves 14, 16 and 18 each have a through bore, illustrated at 15 in FIG.3, through which well fluid may flow when the valve is open. Flanges 86are provided at each end of each flanges brings the facing surfaces ofthe flanges into sealing abutment with each other.

As shown in FIG. 2, each of the valves is provided with a hydraulicoperator 32. It will be appreciated that in readying the well forproduction or for other operations in the well, it will be necessary tooperate the various valves from open to closed and from closed to openfrom time to time in various combinations. Control means are provided inthe copending application of myself and Charles F. Johnson, Ser. No.587,892, filed Oct. 19, I966 now abandoned, entitled Valve Operator, foroperating all of the valves by means of hydraulic fluid supplied fromthe surface through a single hydraulic line. The unit provided for thispurpose in my said copending application is known as a sequencing valve,and such a sequencing valve may be used for the control device 22 shownherein. Other apparatus suitable for controlling flow of fluid to thevalve operators may also be used. For example the apparatus described inUS. Pat. No. 2,64'l,280,'issued on June 9, 1953 to H. G. Fleischhauer,could easily be adapted to such a use.

In FIG. 3, valve 14 is shown with a form of valve operator 32 which maybe used in the wellhead assembly of this invention. It will beappreciated that the structure shown in FIG. 3 is also typical of thestructures of valves 16 and 18 and their operators. As shown, theoperator 32 comprises an elongated housing 34 which is connected bymeans of a coupling 36 to a spacer 38 which also serves as the bonnetfor the valve 14. Thus, spacer 38 maybe considered to be a part of thevalve or a part of the operator. The spacer 38 is connected to the valveby means'of a clamp 40. A cover 42 closes the outer end of the operatorhousing 34. The operator housing is provided with a cylindrical bore 44extending longitudinally thereof to form a cylinder in which a piston 46is sealingly received, piston rings 48 and 50 being provided on thepiston to form a seal with the cylinder. The piston 46 is fastened to apiston rod 52 by means of a nut 54. The piston rod extendslongitudinally through and extends out the lower end of the housing 34and is connected, as by means of the J-slot connector 56, to the valvestem 58. The valve stem, as is well known in the art, is connected tothe gate of the valve, and longitudinal movement of the valve stemserves to open and close the valve by lowering and raising the gate.

In the embodiment shown, the valve is biased toward a closed position bymeans of the concentric springs 60 and 62 extending between the piston46 and a spring washer 64 surrounding the piston rod at the lower end ofthe cylinder and resting on the end of the spacer 38. Y

A longitudinal passageway 66 is provided in the wall of the housing 34extending to the upper end of the housing and communicating with acavity 68 in the cap 42. At the lower end of the housing the passageway66 is positioned to communicate with a corresponding passageway 70 inthe wall of the spacer which extends longitudinally thereof to both endsof the spacer. A connector 72 extends between the abutting flanges andsealingly connects the two passageways 66 and 70 v by means of O-ringseals 74, which are adapted to form seals with enlarged counter bores inthe facing ends of the passageways 66 and 70. At the opposite end of thepassageway 70a similar connector 72 is provided to provide communicationbetween the passageway 70 in the spacer and another passageway 76 formedin the wall of the body of valve 14.

To provide actuating fluid to the opposite side of the piston 46 aradial passageway is formed in the wall of the operator housing 34 andis plugged as by means ofa plug 81 at its outer end. An intersectinglongitudinal passageway 82 extends from the radial passageway 78 to thelower end of the housing where it is in communication with alongitudinally extending passageway in the spacer which in turncommunicates with a passageway similar to passageway 76 in the valvebody. Connection between these passageways may be provided similarly asis shown for the passageways 66, 70 and 76.

A counter bore 84 is provided in the end of the flange 86 of the valvewhich is received within the clamp 24 shown in H0. 1. This counter borereceives a connector 72 to provide the fluid communication between thevalve body and a passageway 88 in the tee (See FIG. 2). The passageway88 in the wall of the tee 20 extends from a flange corresponding to theflange 86 on the valve 14 to a flange 90 on the tee which is providedfor connection thereto of the control device 22. Another connector 72intermediate the flange 90 and the control device provides communicationbetween the passageway 88 and the control device.

A similar passageway 92 in the opposite side of the tee provides fluidcommunication with the operator 32 for valve 16. It will be appreciatedthat two of each of such passageways 88 and 92 are provided for eachvalve although not all the passageways are shown on the drawing.

A hydraulic line 94 which leads to the surface of the water is connectedinto the valve control device at 96. This line may provide hydraulicfluid for operation of all of the valves in the Christmas tree".

It will be appreciated that a Christmas tree of the type shown anddescribed herein may be assembled at the surface and that allconnections for operating fluid are automatically made upon theassembling of the various elements together, provided that theconnectors 72 are placed in the counter bores provided during theassembly. Upon assembly in this manner all of the fluid lines forconduction of operating fluids are wholly enclosed in the variouselements of the Christmas tree and are not exposed to the elements norneed they be serviced in any manner after the Christmas tree is loweredinto the water. Thus, the difficulty of lowering, in this case, sixhydraulic lines to the wellhead and connecting them to the valves at thedesired locations is avoided. Also the problems which are inherent inexposed connections of small high pressure lines are avoided. A wellheadassembly is, therefore, provided in which only a single externalconnection for actuating fluid is required.

Although a preferred embodiment of the invention has been shown anddescribed herein, it is not intended that the invention be limited tothis embodiment since various modifications thereof will be apparent tothose skilled in the art. The invention is, therefore, to be limitedonly in the manner defined by the appended claims.

I claim:

1. A Christmas tree comprising:

a plurality of wellhead valves;

an adapter for connecting said valves together;

said adapter including well-fluid passages therethrough;

fluid-actuable operator means on each valve for operating the valvebetween open and closed positions;

control meansfor controlling the flow of operating fluid to and fromsaid operator means; and

communicating passageways in the walls of said valves, said operatormeans, and said adapter connecting said control means to said operatormeans without external conduits.

2. A Christmas tree as defined by claim 1 wherein: each valve has asurface abutting a surface on an operator means and another surfaceabutting a surface on said adapter; and

said passageways communicate through said abutting surfaces.

3. A Christmas tree comprising:

a master valve positionable above a well;

a swab valve above and spaced away from said master valve;

aligned well-fluid passageways in said valves;

adapter means intermediate said valves with an aligned well-fluidpassageway therethrough;

a side-opening well-fluid passageway in said adapter means;

a wing valve having a well-fluid passageway communicating with saidside-opening passageway;

each of said valves and said adapter means having abutting surfacessurrounding said well-fluid passageways;

fluid-actuable operator means on each valve for operating the valvebetween open and closed positions;

abutting surfaces between each operator means and the valve which itoperates;

control means on said adapter means for controlling the flow ofoperating fluid to and from said operator means; and

a series of communicating fluid passages from said control means to eachoperator means formed in the walls of said adaptor means, the valve andsaid operator means, communication being accomplished across saidabutting surfaces.

4. A Christmas tree as defined by claim 3, and including:

connector means for automatically and sealingly connecting said seriesof communicating fluid passages upon moving said surfaces into abutment.

